Skip to main content

Compromised investigations and scene preservation

Hazard Knowledge

At any time during and after an operational incident there may be a need to carry out some form of investigation. This may be as a result of an adverse health and safety event, suspected criminal activity or a statutory body carrying out their duties. The possible types of post incident investigation include:

  • Fire investigation
  • Health and safety event investigation e.g. accident, near miss/hit, cause for concern
  • Criminal investigation
  • Investigations by: 
    • Health and safety regulatory bodies
    • Environmental agencies
    • Local authority
    • Transport enforcing authorities, e.g. Air Accident Investigation Bureau
  • Attendance at coroner's court (or equivalent)

At an incident, it is important to consider the need to preserve the scene for investigation. Actions taken at all stages of an incident affect the preservation of evidence. Because of this, conducting an investigation should be at the forefront of an incident commander's mind during the dynamic phases of an incident and during post-incident activity.

Failure to properly secure and manage a scene may allow evidence to be disturbed or destroyed. Evidence can be damaged by:

  • Exposure to the elements
  • Animal disturbance
  • Material being moved
  • Foreign objects being introduced
  • Cross contamination by responders

Investigation of an incident is a complex and specialist task and it is important that the scene is preserved as completely as possible and accurate records kept following the conclusion of the incident. They may be required as evidence in legal proceedings.

The need to investigate should not affect bringing an incident to a safe and satisfactory conclusion nor interfere with incident objectives and priorities. During an incident, there may be an opportunity to scale down incidents and allow investigators into safe areas, but this should not affect ongoing operations and scene safety must remain a priority. Nominating safe paths to and from the scene will assist in protecting evidence and the safety of investigators.

Allowing evidence to be lost or contaminated and incorrect or incomplete recording of actions that may affect an investigation can have serious consequences. Understanding the reasons for investigation, helps establish why failing to preserve a scene can be hazardous. Investigations are conducted to:

  • Help prevent similar events from occurring by identifying trends
  • Enable better targeting of enforcement and advice
  • Assist in the prosecution of offenders
  • Assist coroners' courts
  • Contribute to national statistics through accurate reporting on the Incident Recording System (IRS)
  • Assist with advising and educating young people
  • Assess the effect of fire and rescue service intervention
  • Understand the behaviour that led to the incident
  • Understand the functioning of safety features

It is the responsibility of all responders to support the investigative process which, if successful, reduces the frequency and severity of incidents and improves intervention. Any fire and rescue service action that impedes or prevents investigation affects this process and may lead to members of the public and responders being subject to unnecessary risk.

Investigating a scene is inherently dangerous. Every person involved in the activity should aim to minimise the risk involved while performing as full an investigation as possible. Even post-incident, incident commanders should consider the following factors to minimise risk:

  • Identify the hazards, assess and record the risks at the scene and establish the appropriate control measures (including personal protective equipment (PPE) and respiratory protective equipment (RPE))
  • Identify the type, location, extent and circumstances of the incident. Identify and evaluate available information
  • Identify which specialists and other agencies need to be involved
  • To aid this process, a risk assessment must be carried out by the investigating officer at all investigations

See National Operational Guidance- Legal register for further details.

Contaminating a scene

Contamination of the scene by introducing materials that may be identified as potential evidence should be avoided.

Introducing foreign materials is referred to as contamination transfer and may indicate poor scene management procedures. Contamination transfer may occur when items are dropped at the scene or inside cordon areas. Materials that may cause contamination transfer include personal protective equipment (PPE), gloves, cigarettes, drink bottles and other consumables. Any contaminated transfer creates false evidence that could waste significant time and resources to identify, recover and process forensically during the key phase of an investigation.

DNA evidence is robust and can withstand heat, soot contamination and water. However, in many cases, it may not be immediately apparent where the DNA evidence has come from. Any blood injuries to an authorised person that occur within the inner cordon (not only the scene) should be noted and brought to the attention of the relevant agency, particularly in a police-led investigation.